* [PATCH v3 04/22] perf/events: replace READ_ONCE() with standard page table accessors
[not found] <20251113014656.2605447-1-samuel.holland@sifive.com>
@ 2025-11-13 1:45 ` Samuel Holland
2025-11-13 19:10 ` David Hildenbrand (Red Hat)
0 siblings, 1 reply; 2+ messages in thread
From: Samuel Holland @ 2025-11-13 1:45 UTC (permalink / raw)
To: Palmer Dabbelt, Paul Walmsley, linux-riscv, Andrew Morton,
David Hildenbrand, linux-mm
Cc: devicetree, Suren Baghdasaryan, linux-kernel, Mike Rapoport,
Michal Hocko, Conor Dooley, Lorenzo Stoakes, Krzysztof Kozlowski,
Alexandre Ghiti, Emil Renner Berthing, Rob Herring,
Vlastimil Babka, Liam R . Howlett, Anshuman Khandual,
Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
Namhyung Kim, linux-perf-users, Samuel Holland
From: Anshuman Khandual <anshuman.khandual@arm.com>
Replace READ_ONCE() with standard page table accessors i.e pxdp_get() which
anyways default into READ_ONCE() in cases where platform does not override.
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-perf-users@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20251006042622.1743675-1-anshuman.khandual@arm.com/
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
---
Changes in v3:
- Replace my patch with Anshuman Khandual's patch from LKML
Changes in v2:
- New patch for v2
kernel/events/core.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 1fd347da9026..fa4f9165bd94 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -8122,7 +8122,7 @@ static u64 perf_get_pgtable_size(struct mm_struct *mm, unsigned long addr)
pte_t *ptep, pte;
pgdp = pgd_offset(mm, addr);
- pgd = READ_ONCE(*pgdp);
+ pgd = pgdp_get(pgdp);
if (pgd_none(pgd))
return 0;
@@ -8130,7 +8130,7 @@ static u64 perf_get_pgtable_size(struct mm_struct *mm, unsigned long addr)
return pgd_leaf_size(pgd);
p4dp = p4d_offset_lockless(pgdp, pgd, addr);
- p4d = READ_ONCE(*p4dp);
+ p4d = p4dp_get(p4dp);
if (!p4d_present(p4d))
return 0;
@@ -8138,7 +8138,7 @@ static u64 perf_get_pgtable_size(struct mm_struct *mm, unsigned long addr)
return p4d_leaf_size(p4d);
pudp = pud_offset_lockless(p4dp, p4d, addr);
- pud = READ_ONCE(*pudp);
+ pud = pudp_get(pudp);
if (!pud_present(pud))
return 0;
--
2.47.2
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